<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Pdf
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: ElementFactory.php 18993 2009-11-15 17:09:16Z alexander $
 */


/** Zend_Pdf_ElementFactory_Interface */
require_once 'Zend/Pdf/ElementFactory/Interface.php';

/**
 * PDF element factory.
 * Responsibility is to log PDF changes
 *
 * @package    Zend_Pdf
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Pdf_ElementFactory implements Zend_Pdf_ElementFactory_Interface
{
	/**
	 * List of the modified objects.
	 * Also contains new and removed objects
	 *
	 * Array: ojbectNumber => Zend_Pdf_Element_Object
	 *
	 * @var array
	 */
	private $_modifiedObjects = array();

	/**
	 * List of the removed objects
	 *
	 * Array: ojbectNumber => Zend_Pdf_Element_Object
	 *
	 * @var SplObjectStorage
	 */
	private $_removedObjects;

	/**
	 * List of registered objects.
	 * Used for resources clean up when factory is destroyed.
	 *
	 * Array of Zend_Pdf_Element objects
	 *
	 * @var array
	 */
	private $_registeredObjects = array();

	/**
	 * PDF object counter.
	 * Actually it's an object number for new PDF object
	 *
	 * @var integer
	 */
	private $_objectCount;


	/**
	 * List of the attached object factories.
	 * Array of Zend_Pdf_ElementFactory_Interface objects
	 *
	 * @var array
	 */
	private $_attachedFactories = array();


	/**
	 * Factory internal id
	 *
	 * @var integer
	 */
	private $_factoryId;

	/**
	 * Identity, used for factory id generation
	 *
	 * @var integer
	 */
	private static $_identity = 0;


	/**
	 * Internal cache to save calculated shifts
	 *
	 * @var array
	 */
	private $_shiftCalculationCache = array();


	/**
	 * Object constructor
	 *
	 * @param integer $objCount
	 */
	public function __construct($objCount)
	{
		$this->_objectCount    = (int)$objCount;
		$this->_factoryId      = self::$_identity++;
		$this->_removedObjects = new SplObjectStorage();
	}


	/**
	 * Factory generator
	 *
	 * @param integer $objCount
	 * @return Zend_Pdf_ElementFactory_Interface
	 */
	static public function createFactory($objCount)
	{
		require_once 'Zend/Pdf/ElementFactory/Proxy.php';
		return new Zend_Pdf_ElementFactory_Proxy(new Zend_Pdf_ElementFactory($objCount));
	}

	/**
	 * Close factory and clean-up resources
	 *
	 * @internal
	 */
	public function close()
	{
		$this->_modifiedObjects   = null;
		$this->_removedObjects    = null;
		$this->_attachedFactories = null;

		foreach ($this->_registeredObjects as $obj) {
			$obj->cleanUp();
		}
		$this->_registeredObjects = null;
	}

	/**
	 * Get source factory object
	 *
	 * @return Zend_Pdf_ElementFactory
	 */
	public function resolve()
	{
		return $this;
	}

	/**
	 * Get factory ID
	 *
	 * @return integer
	 */
	public function getId()
	{
		return $this->_factoryId;
	}

	/**
	 * Set object counter
	 *
	 * @param integer $objCount
	 */
	public function setObjectCount($objCount)
	{
		$this->_objectCount = (int)$objCount;
	}

	/**
	 * Get object counter
	 *
	 * @return integer
	 */
	public function getObjectCount()
	{
		$count = $this->_objectCount;

		foreach ($this->_attachedFactories as $attached) {
			$count += $attached->getObjectCount() - 1; // -1 as "0" object is a special case and shared between factories
		}

		return $count;
	}


	/**
	 * Attach factory to the current;
	 *
	 * @param Zend_Pdf_ElementFactory_Interface $factory
	 */
	public function attach(Zend_Pdf_ElementFactory_Interface $factory)
	{
		if ( $factory === $this || isset($this->_attachedFactories[$factory->getId()])) {
			/**
			 * Don't attach factory twice.
			 * We do not check recusively because of nature of attach operation
			 * (Pages are always attached to the Documents, Fonts are always attached
			 * to the pages even if pages already use Document level object factory and so on)
			 */
			return;
		}

		$this->_attachedFactories[$factory->getId()] = $factory;
	}


	/**
	 * Calculate object enumeration shift.
	 *
	 * @param Zend_Pdf_ElementFactory_Interface $factory
	 * @return integer
	 */
	public function calculateShift(Zend_Pdf_ElementFactory_Interface $factory)
	{
		if ($factory === $this) {
			return 0;
		}

		if (isset($this->_shiftCalculationCache[$factory->_factoryId])) {
			return $this->_shiftCalculationCache[$factory->_factoryId];
		}

		$shift = $this->_objectCount - 1;

		foreach ($this->_attachedFactories as $subFactory) {
			$subFactoryShift = $subFactory->calculateShift($factory);

			if ($subFactoryShift != -1) {
				// context found
				$this->_shiftCalculationCache[$factory->_factoryId] = $shift + $subFactoryShift;
				return $shift + $subFactoryShift;
			} else {
				$shift += $subFactory->getObjectCount()-1;
			}
		}

		$this->_shiftCalculationCache[$factory->_factoryId] = -1;
		return -1;
	}

	/**
	 * Clean enumeration shift cache.
	 * Has to be used after PDF render operation to let followed updates be correct.
	 */
	public function cleanEnumerationShiftCache()
	{
		$this->_shiftCalculationCache = array();

		foreach ($this->_attachedFactories as $attached) {
			$attached->cleanEnumerationShiftCache();
		}
	}

	/**
	 * Retrive object enumeration shift.
	 *
	 * @param Zend_Pdf_ElementFactory_Interface $factory
	 * @return integer
	 * @throws Zend_Pdf_Exception
	 */
	public function getEnumerationShift(Zend_Pdf_ElementFactory_Interface $factory)
	{
		if (($shift = $this->calculateShift($factory)) == -1) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception('Wrong object context');
		}

		return $shift;
	}

	/**
	 * Mark object as modified in context of current factory.
	 *
	 * @param Zend_Pdf_Element_Object $obj
	 * @throws Zend_Pdf_Exception
	 */
	public function markAsModified(Zend_Pdf_Element_Object $obj)
	{
		if ($obj->getFactory() !== $this) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception('Object is not generated by this factory');
		}

		$this->_modifiedObjects[$obj->getObjNum()] = $obj;
	}


	/**
	 * Remove object in context of current factory.
	 *
	 * @param Zend_Pdf_Element_Object $obj
	 * @throws Zend_Pdf_Exception
	 */
	public function remove(Zend_Pdf_Element_Object $obj)
	{
		if (!$obj->compareFactory($this)) {
			require_once 'Zend/Pdf/Exception.php';
			throw new Zend_Pdf_Exception('Object is not generated by this factory');
		}

		$this->_modifiedObjects[$obj->getObjNum()] = $obj;
		$this->_removedObjects->attach($obj);
	}


	/**
	 * Generate new Zend_Pdf_Element_Object
	 *
	 * @todo Reusage of the freed object. It's not a support of new feature, but only improvement.
	 *
	 * @param Zend_Pdf_Element $objectValue
	 * @return Zend_Pdf_Element_Object
	 */
	public function newObject(Zend_Pdf_Element $objectValue)
	{
		require_once 'Zend/Pdf/Element/Object.php';
		$obj = new Zend_Pdf_Element_Object($objectValue, $this->_objectCount++, 0, $this);
		$this->_modifiedObjects[$obj->getObjNum()] = $obj;
		return $obj;
	}

	/**
	 * Generate new Zend_Pdf_Element_Object_Stream
	 *
	 * @todo Reusage of the freed object. It's not a support of new feature, but only improvement.
	 *
	 * @param mixed $objectValue
	 * @return Zend_Pdf_Element_Object_Stream
	 */
	public function newStreamObject($streamValue)
	{
		require_once 'Zend/Pdf/Element/Object/Stream.php';
		$obj = new Zend_Pdf_Element_Object_Stream($streamValue, $this->_objectCount++, 0, $this);
		$this->_modifiedObjects[$obj->getObjNum()] = $obj;
		return $obj;
	}


	/**
	 * Enumerate modified objects.
	 * Returns array of Zend_Pdf_UpdateInfoContainer
	 *
	 * @param Zend_Pdf_ElementFactory_Interface $rootFactory
	 * @return array
	 */
	public function listModifiedObjects($rootFactory = null)
	{
		if ($rootFactory == null) {
			$rootFactory = $this;
			$shift = 0;
		} else {
			$shift = $rootFactory->getEnumerationShift($this);
		}

		ksort($this->_modifiedObjects);

		$result = array();
		require_once 'Zend/Pdf/UpdateInfoContainer.php';
		foreach ($this->_modifiedObjects as $objNum => $obj) {
			if ($this->_removedObjects->contains($obj)) {
				$result[$objNum+$shift] = new Zend_Pdf_UpdateInfoContainer($objNum + $shift,
				$obj->getGenNum()+1,
				true);
			} else {
				$result[$objNum+$shift] = new Zend_Pdf_UpdateInfoContainer($objNum + $shift,
				$obj->getGenNum(),
				false,
				$obj->dump($rootFactory));
			}
		}

		foreach ($this->_attachedFactories as $factory) {
			$result += $factory->listModifiedObjects($rootFactory);
		}

		return $result;
	}

	/**
	 * Register object in the factory
	 *
	 * It's used to clear "parent object" referencies when factory is closed and clean up resources
	 *
	 * @param string $refString
	 * @param Zend_Pdf_Element_Object $obj
	 */
	public function registerObject(Zend_Pdf_Element_Object $obj, $refString)
	{
		$this->_registeredObjects[$refString] = $obj;
	}

	/**
	 * Fetch object specified by reference
	 *
	 * @param string $refString
	 * @return Zend_Pdf_Element_Object|null
	 */
	public function fetchObject($refString)
	{
		if (!isset($this->_registeredObjects[$refString])) {
			return null;
		}
		return $this->_registeredObjects[$refString];
	}


	/**
	 * Check if PDF file was modified
	 *
	 * @return boolean
	 */
	public function isModified()
	{
		if (count($this->_modifiedObjects) != 0) {
			return true;
		}

		foreach ($this->_attachedFactories as $subFactory) {
			if ($subFactory->isModified()) {
				return true;
			}
		}

		return false;
	}
}

